384 research outputs found
On the Olson and the Strong Davenport constants
A subset of a finite abelian group, written additively, is called
zero-sumfree if the sum of the elements of each non-empty subset of is
non-zero. We investigate the maximal cardinality of zero-sumfree sets, i.e.,
the (small) Olson constant. We determine the maximal cardinality of such sets
for several new types of groups; in particular, -groups with large rank
relative to the exponent, including all groups with exponent at most five.
These results are derived as consequences of more general results, establishing
new lower bounds for the cardinality of zero-sumfree sets for various types of
groups. The quality of these bounds is explored via the treatment, which is
computer-aided, of selected explicit examples. Moreover, we investigate a
closely related notion, namely the maximal cardinality of minimal zero-sum
sets, i.e., the Strong Davenport constant. In particular, we determine its
value for elementary -groups of rank at most , paralleling and building
on recent results on this problem for the Olson constant
Zwei Reinigungssysteme im Vergleich
Das Universitätsspital Basel (USB) ist eines der fünf grössten Gesundheitszentren der Schweiz. Die Abteilung Infrastruktur ist u.a. verantwortlich für die Erbringung von bedürfnisgerechten und den neusten Erkenntnissen entsprechenden Reinigungsdienstleistungen.
Im Rahmen einer Überprüfung der Reinigungsprozesse wurde das Institut für Facility Management (IFM) der Zürcher Hochschule für Angewandte Wissenschaften beauftragt, die Prozesse zu analysieren und mögliche Optimierungspotenziale aufzuzeigen
A comprehensive analysis of interleukin-4 receptor polymorphisms and their association with atopy and IgE regulation in childhood
Background: The interleukin (IL) 4/IL13 pathway is involved in the regulation of IgE production associated with atopic diseases. Numerous polymorphisms have been identified in the coding region of the IL4 receptor alpha chain (IL4Ra) and previous association studies have shown conflicting results. Based on their putative functional role, polymorphisms A148G, T1432C and A1652G, located in the coding region of IL4Ra, were selected for association and haplotype studies in a large German population sample (n = 1,120). Methods: Genotyping was performed using allele-specific PCR and restriction-enzyme-based assays. Haplotypes were estimated, and population-derived IgE percentiles (50% IgE >60 IU/ml, 66% IgE >115 IU/ml and 90% IgE >457 IU/ml) were calculated as outcome variables in a haplotype trend regression analysis. Results: In our population, only polymorphism T1432C showed a trend for a protective effect against atopic rhinitis ( odds ratio, OR: 0.52, 95% confidence interval, CI: 0.26 - 1.02, p = 0.05). When haplotypes were calculated, one haplotype was significantly associated with elevated serum IgE levels at the 50th percentile ( OR 1.60, 95% CI 1.08 - 2.37, p = 0.02). Conclusions: These data indicate that IL4Ra polymorphisms, although suggested to be functionally relevant by in vitro studies, have only a minor influence on IgE regulation in our large population sample. Copyright (C) 2004 S. Karger AG, Basel
Multi-wise and constrained fully weighted Davenport constants and interactions with coding theory
We consider two families of weighted zero-sum constants for finite abelian groups. For a finite abelian group , a set of weights , and an integral parameter , the -wise Davenport constant with weights is the smallest integer such that each sequence over of length has at least disjoint zero-subsums with weights . And, for an integral parameter , the -constrained Davenport constant with weights is the smallest such that each sequence over of length has a zero-subsum with weights of size at most . First, we establish a link between these two types of constants and several basic and general results on them. Then, for elementary -groups, establishing a link between our constants and the parameters of linear codes as well as the cardinality of cap sets in certain projective spaces, we obtain various explicit results on the values of these constants
RNAi-mediated silencing of MLL-AF9 reveals leukemia-associated downstream targets and processes
Background: The translocation t(9;11)(p22;q23) leading to the leukemogenic fusion gene MLL-AF9 is a frequent translocation in infant acute myeloid leukemia (AML). This study aimed to identify genes and molecular processes downstream of MLL-AF9 (alias MLL-MLLT3) which could assist to develop new targeted therapies for such leukemia with unfavorable prognosis. Methods: In the AML cell line THP1 which harbors this t(9; 11) translocation, endogenous MLL-AF9 was silenced via siRNA while ensuring specificity of the knockdown and its efficiency on functional protein level. Results: The differential gene expression profile was validated for leukemia-association by gene set enrichment analysis of published gene sets from patient studies and MLL-AF9 overexpression studies and revealed 425 differentially expressed genes. Gene ontology analysis was consistent with a more differentiated state of MLL-AF9 depleted cells, with involvement of a wide range of downstream transcriptional regulators and with defined functional processes such as ribosomal biogenesis, chaperone binding, calcium homeostasis and estrogen response. We prioritized 41 gene products as candidate targets including several novel and potentially druggable effectors of MLL-AF9 (AHR, ATP2B2, DRD5, HIPK2, PARP8, ROR2 and TAS1R3). Applying the antagonist SCH39166 against the dopamine receptor DRD5 resulted in reduced leukemic cell characteristics of THP1 cells. Conclusion: Besides potential new therapeutic targets, the described transcription profile shaped by MLL-AF9 provides an information source into the molecular processes altered in MLL aberrant leukemia
Literature as Colonial Loot? Towards a Philological Provenance Research
Mit der hier erstmals skizzierten Methode einer philologischen Provenienzforschung lässt sich untersuchen, wie »Oralliteraturen« aus kolonisierten Gebieten nach Europa gelangten. Dieser Transfer wurde in der Forschung bislang weitgehend vernachlässigt, wird aber bereits in der postkolonialen Gegenwartsliteratur verhandelt. Er lieferte das Material für die Poetik der historischen Avantgarden, für Literatur- und Sprachtheorien, aber auch für einen bis heute florierenden Markt an Geschenkbüchern. Um diese exklusiv westlichen Verwertungszusammenhänge aufzubrechen, schlagen wir die Rückgabe von Deutungshoheit als Möglichkeit einer Restitution vor.This article proposes a method for philological provenance research that allows us to examine the transfer of »oral literatures« from colonised areas to Europe. This transfer has received little scholarly attention but is present in contemporary postcolonial narratives. It was substantial not only in consolidating the poetics of the historical avant-gardes and informing literary and linguistic theory, but also in sustaining a market for gift-books still flourishing today. To disrupt these exclusively Western cycles of exploitation, we propose to return the authority of interpretation as a possibility of restitution
Pediatric hepatocellular carcinoma: challenges and solutions
Hepatocellular carcinoma (HCC) is a very rare entity in children, making it nearly impossible to orchestrate Phase II/III studies even as multinational cooperative trials. In contrast to adults, nearly 50% of the children have a response (a-fetoprotein decline and/or tumor shrinkage) to chemotherapeutic agents such as cisplatin and doxorubicin (PLADO), demonstrating that HCC in childhood can be chemotherapy sensitive. As a result, the main treatment options in pediatric HCC focus on systemic drug therapies and resection as the central therapy. In nonmetastatic patients with complete resection upfront, the 5-year event-free survival and overall survival has reached 80%-90%. In almost all reported studies, children received adjuvant chemotherapy (mostly PLADO), but it has never been proven that postoperative chemotherapy is superior to observation. No data are available for the effects of sorafenib. The 3-year survival is <20% in children with unresectable HCC independent of the chemotherapy given preoperatively. Currently, PLADO in combination with sorafenib is recommended with the goal of achieving operability status. Alternatively, data are promising for the combination of sorafenib with gemcitabine and oxaliplatin. For children with nonresectable and nonmetastastic liver tumors, it has been shown that the Milan criteria regarding liver transplantation are not applicable - individual decisions have to be made. Transarterial chemoembolization could be offered to patients with chemotherapy-resistant liver tumors for palliative care or potentially to achieve surgical resectability, and therefore cure. Information about the feasibility or effects of new agents or approaches as discussed in adult HCC patients is not available for childhood HCC. Research has to be done for characterizing the molecular and genomic mechanisms of pediatric HCC to support the development of novel therapeutic approaches and the implementation of personalized medicine
The Extension of the German CERAD Neuropsychological Assessment Battery with Tests Assessing Subcortical, Executive and Frontal Functions Improves Accuracy in Dementia Diagnosis
Alzheimer's disease (AD) is the most common form of dementia. Neuropsychological assessment of individuals with AD primarily focuses on tests of cortical functioning. However, in clinical practice, the underlying pathologies of dementia are unknown, and a focus on cortical functioning may neglect other domains of cognition, including subcortical and executive functioning. The current study aimed to improve the diagnostic discrimination ability of the Consortium to Establish a Registry for Alzheimer's Disease - Neuropsychological Assessment Battery (CERAD-NAB) by adding three tests of executive functioning and mental speed (Trail Making Tests A and B, S-Words).; Logistic regression analyses of 594 normal controls (NC), 326 patients with mild AD and 224 patients with other types of dementia (OD) were carried out, and the area under the curve values were compared to those of CERAD-NAB alone.; All comparisons except AD-OD (65.5%) showed excellent classification rates (NC-AD: 92.7%; NC-OD: 89.0%; NC-all patients: 91.0%) and a superior diagnostic accuracy of the extended version.; Our findings suggest that these three tests provide a sensible addition to the CERAD-NAB and can improve neuropsychological diagnosis of dementia
Improved Prostate-Specific Membrane Antigen (PSMA) Stimulation Using a Super Additive Effect of Dutasteride and Lovastatin In Vitro
Prostate-specific membrane antigen (PSMA)-based imaging improved the detection of primary, recurrent and metastatic prostate cancer. However, in certain patients, a low PSMA surface expression can be a limitation for this promising diagnostic tool. Pharmacological induction of PSMA might be useful to further improve the detection rate of PSMA-based imaging. To achieve this, we tested dutasteride (Duta)-generally used for treatment of benign prostatic enlargement-and lovastatin (Lova)-a compound used to reduce blood lipid concentrations. We aimed to compare the individual effects of Duta and Lova on cell proliferation as well as PSMA expression. In addition, we tested if a combination treatment using lower concentrations of Duta and Lova can further induce PSMA expression. Our results show that a treatment with ≤1 μM Duta and ≥1 μM Lova lead to a significant upregulation of whole and cell surface PSMA expression in LNCaP, C4-2 and VCaP cells. Lower concentrations of Duta and Lova in combination (0.5 μM Duta + 0.5 μM Lova or 0.5 μM Duta + 1 μM Lova) were further capable of enhancing PSMA protein expression compared to a single compound treatment using higher concentrations in all tested cell lines (LNCaP, C4-2 and VCaP)
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